The importance of providing adequate lubrication to each of the movable components inside the crankcase of an internal combustion engine is well known. Without proper lubrication, the engine cannot operate efficiently and will eventually fail. For example, without proper lubrication, the bearings that support the crankshaft will quickly reach very high temperatures resulting in premature bearing failure or at least a substantial reduction in the operating life of the bearing. Accordingly, the lubrication system is a major concern in the design of the engine.
Some lubrication systems include a plurality of devices that mechanically move oil from oil reservoirs to movable components inside the engine housing. These lubrication devices may provide oil to the components mounted to, or connected with, the crankshaft and cam shaft, the cylinder bores and the pistons that move therein, as well as the bearings that support the crankshaft and/or cam shaft.
In the splash and spray lubrication system disclosed in U.S. Pat. No. 1,842,303, the connecting rods are provided with an extension or paddle on their crankshaft ends. Upon crankshaft rotation, the paddles dip into individual oil pits, thereby lubricating the connecting rod assembly, and then sling or spray the oil in the engine housing.
In the lubrication system disclosed in U.S. Pat. No. 1,271,140, a large spur gear is disposed in the bottom portion of the engine housing and is partially immersed in an oil reservoir. Further, the spur gear is disposed below a pinion mounted onto the crankshaft and meshes with the pinion upon rotation of the crankshaft. The pinion drives the spur gear and the spur gear rotates within the oil reservoir, thereby throwing oil outward to lubricate the crankshaft and the cam shaft.
Since the crankshaft bearings are typically located adjacent to the walls of the engine housing, it is often difficult for lubrication devices such as the devices described in the above patents (i.e., the paddle or the spur gear) to throw, spray, or otherwise provide an adequate amount of lubricant to the crankshaft bearings. Consequently, the lubrication systems for these engines must typically be equipped with additional devices for dispersing lubricant specifically in the direction of the crankshaft bearings.
In U.S. Pat. No. 1,842,303, the engine is provided with additional oil reservoirs that are located above each of the crankshaft bearings. Small ports on the bottom of each oil reservoir drip or feed oil onto the top of the bearing. In U.S. Pat. No. 1,271,140, the engine is provided with a second gear to supplement the spur gear that is partially immersed in the oil reservoir. The second gear is above the crankshaft and is rotated on a rotational plane that is turned about 90.degree. from the spur gear. The second gear receives oil thrown by the spur gear and oil deflected by the other rotating components on the crankshaft. The second gear then flings the oil toward each of the crankshaft bearings.